Euclid Telescope Spots 31 Ancient Quasars, Including Earliest Ever Seen

The European Space Agency's Euclid space telescope has discovered 31 of the most ancient quasars ever found, including two that are the earliest ever observed in cosmic history, ESA said.

The two record-breaking objects shone with the light of a trillion Suns when the Universe was only 670 million years old — about 5% of its current age — according to the agency. The findings were described in a Discovery paper led by Daming Yang of Leiden University in the Netherlands.

A window on the cosmic dawn

Quasars are a brief phase in a galaxy's life during which large amounts of material spiral into its central supermassive black hole, releasing enormous energy. During this phase the galaxy's core shines more brightly than anything else in the Universe, often outshining the rest of its host galaxy by hundreds to thousands of times.

Astronomers have hunted the Universe's first quasars for decades because the objects reveal how the earliest supermassive black holes and galaxies took shape. Such quasars are rare — few galaxies had grown large enough to host them — and their primordial light is both faint and easily confused with that of nearer stars.

"These early quasars date back to the Universe's infancy," Yang said. "By finding and studying them, we can better understand how these enormous systems formed and grew so quickly — one of the greatest mysteries in astrophysics."

'Beneath the tip of the iceberg'

Until now, the known early quasars were the bright, easy-to-spot outliers, ESA said, leaving astronomers unable to study the population as a group. Euclid's survey captured not only those luminous objects but also fainter examples, giving scientists a more representative view of the ancient quasar population.

Euclid launched in 2023. Its ability to scan large areas of sky and detect faint light is what made the new haul possible, the agency said.

"Euclid is a true game-changer," Yang said. "Before, we could only find a handful of the very brightest ancient quasars, but Euclid lets us search far more efficiently across huge areas of sky to capture much fainter light. It's a unique tool for quasar hunting."

The discovery, ESA said, pushes observations back to a time when the cosmos was just 5% of its present age, offering a deeper probe of how the first giant black holes assembled so quickly after the Big Bang.